What is the relationship between Vitamin D and knee arthritis? Does vitamin D deficiency cause arthritis? I’ve blogged many times before about Vitamin D and knee arthritis. There are studies on both sides of this fence, with some showing that low vitamin D levels are associated with knee arthritis and other studies showing no such association between vitamin D and knee arthritis. Now a new study stirs up the pot again by concluding that those patients with vitamin D deficiencies develop more arthritic symptoms over time. The new study took almost 800 randomly chosen adults and examined their vitamin D levels compared to their knee and hip pain caused by arthritis over 5 years. This included an assessment of the onset of new knee or hip pain due to arthritis. This study did show a strong association between moderately low vitamin D levels and the onset of arthritis symptoms. In patients with low vitamin D levels, it took knee arthritis pain 5 years to develop while hip arthritis developed more quickly (in a little more than two years). Their data also suggested that while correcting a Vitamin D deficiency may help knee and/or hip pain, supplementing vitamin D to higher levels is unlikely to help (although they didn’t test supplementation, so this is an educated guess). The upshot? The research is all over the map on vitamin D. This paper is better than most in that it followed people for years until the onset of arthritis symptoms, rather than taking a snapshot of levels and trying to tie those to arthritis. In addition, only 4% of patients in this study had a deficiency (<25 nmol/l), so they used stricter criteria for low vitamin D levels than most physicians measuring this vitamin level. For example, a recent 2011 study used 50 nmol/l and found that almost 42% of U.S. adults were deficient. In the meantime, on balance, if you have a deficiency of <25 nmol/l, supplementing your Vitamin D may help your knee and hip arthritis. If you’re low on vitamin D (<75 nmol/l) than the jury is still out. You may be wondering why there’s a map above? Your skin naturally makes vitamin D by exposure to sunlight. That map defines the line in the US (37th parallel) where people don’t make enough vitamin D in their skin (other than the summer months) and as a result, supplementation is recommended.
About the Author
Christopher J. Centeno, M.D. is an international expert and specialist in regenerative medicine and the clinical use of mesenchymal stem cells in orthopedics. He is board certified in physical medicine as well as rehabilitation and in pain management through The American Board of Physical Medicine and Rehabilitation.…